基于中断的键盘驱动

时间：2010-08-01 来源：unixeye

#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/miscdevice.h>
#include <mach/regs-gpio.h>
#include <mach/hardware.h>
#include <asm/uaccess.h>
#include <asm/irq.h>
#define DEVICE_NAME "Key-16"
#define KEY_MAJOR   232 static int keyValue; static DECLARE_WAIT_QUEUE_HEAD(key_waitq); static volatile int ev_press = 0; struct key_irq_desc
{
    int irq;
    unsigned long flags;
    char *name;
}; static struct key_irq_desc key_irqs [] = {
    {IRQ_EINT19, IRQF_TRIGGER_FALLING, "KSCAN1"},
    {IRQ_EINT11, IRQF_TRIGGER_FALLING, "KSCAN2"},
    {IRQ_EINT2, IRQF_TRIGGER_FALLING, "KSCAN3"},
    {IRQ_EINT0, IRQF_TRIGGER_FALLING, "KSCAN4"},
}; static void set_pin(void)
{
    s3c2410_gpio_cfgpin(S3C2410_GPG2,S3C2410_GPG2_OUTP);
    s3c2410_gpio_cfgpin(S3C2410_GPG6,S3C2410_GPG6_OUTP);
    s3c2410_gpio_cfgpin(S3C2410_GPE11,S3C2410_GPE11_OUTP);
    s3c2410_gpio_cfgpin(S3C2410_GPE13,S3C2410_GPE13_OUTP);     s3c2410_gpio_setpin(S3C2410_GPG2,0);
    s3c2410_gpio_setpin(S3C2410_GPG6,0);
    s3c2410_gpio_setpin(S3C2410_GPE11,0);
    s3c2410_gpio_setpin(S3C2410_GPE13,0);
}
static int Key_16_scan(void)
{
    s3c2410_gpio_cfgpin(S3C2410_GPF0,S3C2410_GPF0_INP);     s3c2410_gpio_cfgpin(S3C2410_GPF2,S3C2410_GPF2_INP);
    s3c2410_gpio_cfgpin(S3C2410_GPG3,S3C2410_GPG3_INP);     s3c2410_gpio_cfgpin(S3C2410_GPG11,S3C2410_GPG11_INP);     s3c2410_gpio_setpin(S3C2410_GPE11,0);s3c2410_gpio_setpin(S3C2410_GPE13,1);
    s3c2410_gpio_setpin(S3C2410_GPG2,1);s3c2410_gpio_setpin(S3C2410_GPG6,1);
    if(s3c2410_gpio_getpin(S3C2410_GPF0) == 0) return 0x0a;
    if(s3c2410_gpio_getpin(S3C2410_GPF2) == 0) return 0x07;
    if(s3c2410_gpio_getpin(S3C2410_GPG3) == 0) return 0x04;
    if(s3c2410_gpio_getpin(S3C2410_GPG11) == 0) return 0x01;     s3c2410_gpio_setpin(S3C2410_GPE11,1);s3c2410_gpio_setpin(S3C2410_GPE13,0);
    s3c2410_gpio_setpin(S3C2410_GPG2,1);s3c2410_gpio_setpin(S3C2410_GPG6,1);
    if(s3c2410_gpio_getpin(S3C2410_GPF0) == 0) return 0x0C;
    if(s3c2410_gpio_getpin(S3C2410_GPF2) == 0) return 0x09;
    if(s3c2410_gpio_getpin(S3C2410_GPG3) == 0) return 0x06;
    if(s3c2410_gpio_getpin(S3C2410_GPG11) == 0) return 0x03;     s3c2410_gpio_setpin(S3C2410_GPE11,1);s3c2410_gpio_setpin(S3C2410_GPE13,1);
    s3c2410_gpio_setpin(S3C2410_GPG2,0);s3c2410_gpio_setpin(S3C2410_GPG6,1);
    if(s3c2410_gpio_getpin(S3C2410_GPF0) == 0) return 0x10;
    if(s3c2410_gpio_getpin(S3C2410_GPF2) == 0) return 0x0F;
    if(s3c2410_gpio_getpin(S3C2410_GPG3) == 0) return 0x0E;
    if(s3c2410_gpio_getpin(S3C2410_GPG11) == 0) return 0x0D;     s3c2410_gpio_setpin(S3C2410_GPE11,1);s3c2410_gpio_setpin(S3C2410_GPE13,1);
    s3c2410_gpio_setpin(S3C2410_GPG2,1);s3c2410_gpio_setpin(S3C2410_GPG6,0);
    if(s3c2410_gpio_getpin(S3C2410_GPF0) == 0) return 0x0B;
    if(s3c2410_gpio_getpin(S3C2410_GPF2) == 0) return 0x08;
    if(s3c2410_gpio_getpin(S3C2410_GPG3) == 0) return 0x05;
    if(s3c2410_gpio_getpin(S3C2410_GPG11) == 0) return 0x02;
    else return 0; } static irqreturn_t Key_16_interrupt(int irq,void *dev_id)
{
    disable_irq_nosync(irq);
    ev_press = 1;
    wake_up_interruptible(&key_waitq);
    enable_irq(irq);
    return IRQ_RETVAL(IRQ_HANDLED);
}
static int Key_16_open(struct inode *inode, struct file *file)
{
    int i;
    int err;     set_pin();

    for(i = 0; i < sizeof(key_irqs)/sizeof(key_irqs[0]); i++)
    {
        err = request_irq(key_irqs[i].irq, Key_16_interrupt,key_irqs[i].flags, key_irqs[i].name,(void *)&keyValue);
        if(err)
            break;
    }     return 0;
} static int Key_16_read(struct file *file, char __user *buff, size_t count, loff_t *offp)
{
    unsigned long err;     wait_event_interruptible(key_waitq, ev_press);
    ev_press = 0;     keyValue = Key_16_scan();

    s3c2410_gpio_cfgpin(S3C2410_GPF0,S3C2410_GPF0_EINT0);     s3c2410_gpio_cfgpin(S3C2410_GPF2,S3C2410_GPF2_EINT2);
    s3c2410_gpio_cfgpin(S3C2410_GPG3,S3C2410_GPG3_EINT11);     s3c2410_gpio_cfgpin(S3C2410_GPG11,S3C2410_GPG11_EINT19);
    set_pin();
    if(keyValue != 0)
    {

    err = copy_to_user(buff, &keyValue, min(sizeof(keyValue), count));
    memset(&keyValue, 0, sizeof(keyValue));     return err ? -EFAULT : 0;
    }
    return 0;
} static struct file_operations Key_16_fops =
{
    .owner = THIS_MODULE,
    .open = Key_16_open,
    .read = Key_16_read,
}; static struct miscdevice misc = {
.minor = MISC_DYNAMIC_MINOR,
.name = DEVICE_NAME,
.fops = &Key_16_fops,
}; static int __init Key_16_init(void)
{
    int ret;

    ret = misc_register(&misc);
    printk (DEVICE_NAME" initialized\n");     return ret;
} static void __exit Key_16_exit(void)
{
    misc_deregister(&misc);
} module_init(Key_16_init);
module_exit(Key_16_exit);